In the past, relative movement between the metal stabilizer bar and the rubber bushing has lead to an annoying squeaking noise when the automobile is in use. Several solutions were devised to reduce or eliminate the noise problem. One solution was to provide a surface on the bushing which has a low coefficient of friction such as polymers of polytetraflouroethylene. However, this solution presented problems with expense, and durability.
An alternative solution is presented in Hein U.S. Pat. No. 4,854,766 which is incorporated by reference as if fully set forth herein. In this solution, the mount assembly has an elastomeric inner sleeve which is separately mounted around the sway bar and which contacts an outer sleeve. Either the outer surface of the inner sleeve, or the inner surface of the outer sleeve, or both, are provided with a low friction surface so that any slippage caused by movement between the mount assemblies and the bar occurs between the elastomeric materials in radially spaced relation away from the bar.
In accordance with the present invention, a bushing assembly is provided and it includes means to shift the interface of slippage to the interface between the inner sleeve and the innerliner(i.e. outer sleeve). Specifically, the bushing assembly permits ease of rotational movement. However, the present invention also provides means to limit axial slippage. In particular, the means to inhibit the slippage provides mating surfaces so that there is an increased coefficient of friction between the surfaces as the two members slip further out of axial alignment. In particular these surfaces can be provided by either a flange which inhibits axial movement beyond a certain distance or these surfaces can be provided by mating conical surfaces or both. Thus, the present invention inhibits the inner sleeve from becoming disengaged from the innerliner (outer sleeve).
In addition, the present invention eliminates one of the longitudinal slits in either the inner sleeve or the outer sleeve.
Thus, the present design eliminates the potential presented by the prior art design for the slits in the inner sleeve and the outer sleeve to catch if these two slits should become aligned.
Moreover, the invention accomplishes the foregoing objectives while providing a mount assembly that is relatively simple to assemble and is economical.